Conventional blenders incorporate a mechanically-driven impeller rotatably mounted within a removable blender cup. Many blenders have the drive motor mounted in the base under the cup or off to the side of the cup.
Blenders can be combined with ice shavers in a single unit, for example, for use in restaurants or bars to produce frozen drinks. DC brushless motors can be used for blender/shaver machines. These motors use a comparatively heavy rotor formed of a sector-like array of permanent magnets. Blending of a mass of shaved or cubed ice and liquid, particularly on start up or during a “freeze up” of a frozen drink, requires a comparatively high torque.
The power factor of an AC electric power system is defined as the ratio of the real power flowing to the load (e.g., a motor) to the apparent power, and is a dimensionless number between 0 and 1 (frequently expressed as a percentage, e.g. 0.5 pf=50% pt). Real power is the capacity of the circuit for performing work in a particular time. Apparent power is the product of the current and voltage of the circuit. Due to energy stored in the load and returned to the source, or due to a non-linear load that distorts the wave shape of the current drawn from the source, the apparent power can be greater than the real power. In an electric power system, a load with low power factor draws more current than a load with a high power factor for the same amount of useful power transferred. Thus, a circuit with a low power factor will use higher currents to transfer a given quantity of real power than a circuit with a high power factor.
Where reactive loads are present, such as with capacitors or inductors, energy storage in the loads result in a time difference between the current and voltage waveforms. During each cycle of the AC voltage, extra energy, in addition to any energy consumed in the load, is temporarily stored in the load in electric or magnetic fields, and then returned to the power grid a fraction of a second later in the cycle. The “ebb and flow” of this nonproductive power increases the current in the line and creates electrical noise in the power grid. Inductive loads such as motors (or any type of wound coil) consume reactive power with the current waveform lagging the voltage. Inductive loads will absorb energy during part of the AC cycle, which is stored in the device's magnetic or electric field, only to return this energy back to the power grid during the remainder of the cycle, which can create electrical noise.